Dear list,

I wanted to draw some nice pictures using TikZ and pgfplots, but then I
noticed that the colors of the ticks in my pgfplots graph were unusually
bright and it looked very weird.   So I set up a test

> \usemodule[tikz]
> \starttext
> \starttikzpicture
>   \draw[help lines,very thick] (0,0) -- (1,0);
> \stoptikzpicture
> 
> \externalfigure[test-crop]
> \stoptext

where I produced test-crop.pdf from the following plain TeX sample,
which I also typeset with LuaTeX 0.95 (to make sure it's not a LuaTeX
regression).

> \input luatex85.sty
> \input tikz
> \tikzpicture
>   \draw[help lines,very thick] (0,0) -- (1,0);
> \endtikzpicture
> \bye

Attached you find the output of the ConTeXt example and you can see that
the color of the upper line (the one produced with TikZ inside ConTeXt)
has a much brighter color than the one produced with plain TeX.

I'm using ConTeXt MkIV distributed with TL 2016.

How can I adjust the colors in ConTeXt to match the ones produced by
plain TeX?  I need the adjustment in that direction, because I also have
old images produced with plain TeX/LaTeX that I'd like to seamlessly
integrate in my ConTeXt documents.

Cheers,
Henri